IUGS Classification Fine Grain

Question 1

Compromise >20% quartz and alkali feldspar/ plagioclase 40-90%

Answer 1

Rhyolite

Question 2

Felsics compromising >20% quartz and alkali feldspar/ plagioclase <0.5. The extrusive equivalent of grandiorite.

Answer 2

Dacite

Question 3

Felsic compromisinf 0-5% quart and alkali feldspar/ total feldspar: 0.65-0.9. Extrusive equivalent of syenite

Answer 3

Trachyte

Question 4

Felsic compromising 0-5% quartz and alkali feldspar/ total feldspar 0.35 - 0.65. Extrusive equivalent of monzorite.

Answer 4

Latite

Question 5

0-20% quartz, and >65% of feldspar being plagioclase. Fine grained equivalent of diorite.

Answer 5

Andesite

Question 6

A general term for the fine-grained mafic rocks commonly extrusive.

Answer 6

Basalt

Question 7

Fine-grained felsic igneous lacking of quartz, with felsic comprising 10-60% foids and alkali feldspar/ total feldspar >0.9. Fine grained equivalent of nephaline syenite.

Answer 7

Phonolite

Question 8

Felsics comprising 10-60% foids and alkali feldspar/ total feldspar <0.1, <10% olivine

Answer 8

Tephrite

Question 9

Felsic comprising 10-60% foids and alkali feldspar/ total feldspar <0.1, >10% olivine.

Answer 9

Basanite

Question 10

Fine grained igneous rocks that contain <90% mafics and foids >90% of felsics

Answer 10

Foidite

Question 11

A classification scheme for volcanic rocks based on their bulk chemical composition.

Answer 11

Total alkali vs Silica Diagram or TAS